Summary:Neuroblastoma is one of the frequent tumor of childhood. The tumorsuppresor, p27(KIP1), is a prognostic factor and correlates with a favourable prognosis of neuroblastoma disease. Tat-fusion-protein is a newly found tool for proteintransduction and is an alternative to conventional gentherapy. In the present work I create the Tat-p27(KIP1)-fusion protein and transduced it into neuroblastoma cells. The consequent results in cell cycle situation were investigated to understand more about the prognostic meanings of p27(KIP1) in neuroblastomas.